Note: this documentation not full, ReflectionObject::export($exception):
<?php
Object of class [  class Exception implements Throwable ] {
  - Properties [7] {
    Property [  protected $message ]
    Property [  private $string ]
    Property [  protected $code ]
    Property [  protected $file ]
    Property [  protected $line ]
    Property [  private $trace ]
    Property [  private $previous ]
  }
  - Methods [11] {
    Method [  final private method __clone ] {
    }
    Method [  public method __construct ] {
      - Parameters [3] {
        Parameter #0 [  $message ]
        Parameter #1 [  $code ]
        Parameter #2 [  $previous ]
      }
    }
    Method [  public method __wakeup ] {
    }
    Method [  final public method getMessage ] {
    }
    Method [  final public method getCode ] {
    }
    Method [  final public method getFile ] {
    }
    Method [  final public method getLine ] {
    }
    Method [  final public method getTrace ] {
    }
    Method [  final public method getPrevious ] {
    }
    Method [  final public method getTraceAsString ] {
    }
    Method [  public method __toString ] {
    }
  }
}
?>
Missed:
    Property [  private $string ]
    Property [  private $trace ]
    Property [  private $previous ]
    Method [  public method __wakeup ] {
    }